Final answer:
The author uses descriptions to convey the end result of the competition between silent movies and talking movies by demonstrating the popularity of the new technical method of adding sound to movies.
Step-by-step explanation:
The author uses descriptions to convey the end result of the competition between silent movies and talking movies by demonstrating how a new technical method with better features is typically more popular. In the late 1920s, talking pictures emerged and quickly became the dominant form of motion pictures, replacing silent films. This shift in popularity indicates that the new technical method of adding sound to movies was preferred by audiences over silent films.